1. Field of the Invention
The present invention relates to cellular communications networks in general and more particularly, to repeater-based cellular coverage switching across cellular donor sites or micro cellular sites.
2. Discussion of the Related Art
A known problem in repeater-based cellular coverage systems regards excessive traffic load on cellular donor sites. The problem is caused by the limited load capacity of a typical cellular site and the dynamic and difficult-to-predict traffic load directed to the cellular site by one or more repeaters. The problem is made more acute consequent to the insertion of additional repeaters into the cellular coverage system. Such repeaters are typically used to provide coverage to zones having coverage problems such as, for example, indoor spaces enclosed within massive architectural structures or outdoor areas where natural or man-made obstacles block the cellular signals. Typically, the new repeaters are set up and activated without consideration for the capacity loads of and the existing traffic load of cellular donor sites that are designed to provide service to the repeaters A typical repeater installed for a large architectural structure is connected to one or more external (donor) antennas and to one or more internal (null) antennas. At installation the directions of the donor antennas are pre-set such as to point at different cellular donor sites. In accordance with the specific network architecture the cellular donor site could handle simultaneously several repeaters as well as non-repeater-based traffic.
The traffic loads generated by the newly inserted repeater could be extremely varied. The variance could be based on the periods of the day. Thus, for example, in a nighttime entertainment center, such as a nightclub, located in the architectural structure served by the new repeater the volume of the cellular activity could widely differ between daylight hours and late nighttime hours, Depending on the load capacity of the cellular donor site during peak traffic periods the cellular traffic generated in the nighttime entertainment site could swamp the cellular donor site. The overload could cause substantial deterioration in the quality of the cellular service. Setting up of connections could be delayed and established connections could be terminated in an unwanted and unanticipated manner. On the other hand during the off-peak hours of the nighttime entertainment site it is possible that one or more adjacent cellular donor sites that are providing service for a daytime shopping center, for example, could be overloaded with heavy cellular traffic while the cellular donor site serving the nighttime entertainment site could be significantly under-utilized.
Thus, there is a need for a new apparatus and method to provide the capability for balancing the cellular traffic load across cellular donor sites. The load balancing will be achieved by cellular coverage switching or by dynamically re-routing cellular traffic between coverage zones and cellular donor sites. The traffic will be directed away from overloaded cellular donor sites during peak periods of cellular traffic periods towards other cellular donor sites that are under-utilized within the same period.